1. Field of Invention
The present invention relates generally to the field of wireless communication and data networks. More particularly, in one exemplary aspect, the invention is directed to methods and apparatus for automatic reception of selected segments of information (e.g., system information) in receivers, such as may be useful for inter alia improving power consumption, and/or minimizing processor burden.
2. Description of Related Technology
Universal Mobile Telecommunications System (UMTS) is an exemplary implementation of a “third-generation” or “3 G” cellular telephone technology. The UMTS standard is specified by a collaborative body referred to as the 3rd Generation Partnership Project (3GPP). The 3GPP has adopted UMTS as a 3G cellular radio system targeted for inter alia European markets, in response to requirements set forth by the International Telecommunications Union (ITU). The ITU standardizes and regulates international radio and telecommunications. Enhancements to UMTS will support future evolution to fourth generation (4G) technology.
A current topic of interest is the further development of UMTS towards a mobile radio communication system optimized for packet data transmission through improved system capacity and spectral efficiency. In the context of 3GPP, the activities in this regard are summarized under the general term “LTE” (for Long Term Evolution). The aim is, among others, to increase the maximum net transmission rate significantly in the future, namely to speeds on the order of 300 Mbps in the downlink transmission direction and 75 Mbps in the uplink transmission direction.
Information and Pilot Channels
Information channels (such as Pilot Channels) are used in many prior art cellular mobile radio communication systems. Such channels provide user equipment (UE) with useful information such as for example broadcasts of basic system information. Such information may be crucial during, inter cilia, initial “wake-up” and registration, estimating potential base station (BS) service reception for handover (i.e. hand-off), etc. Various approaches to information (e.g., pilot) channel messaging are evidenced throughout the prior art. For example, in Interim Standard 95 (IS-95, CDMA), a pilot channel is used by mobile devices to initially determine the existence of base stations, and/or support multipath compensation.
Unfortunately, such information channels have a relatively high cost in terms of bandwidth when compared to other useful data channels. Generally speaking, these channels are the most robust and simplest coded channels of the network. When compared to the rest of the network bandwidth utilization (which is densely coded), the information distribution (pilot) resources are significantly underutilized. In some cases, a cellular pilot channel may use up to a fifth of the overall spectral resources, while providing little to no additional information to the user equipment (UE) population during normal operation.
Recently, significant research has been conducted to improve the utilization of information and pilot channels. For example, proposed improvements to pilot channels increase the information capacity of pilot channel messaging. Such proposed pilot channels have the potential to provide significant benefits for devices that are actively receiving and monitoring the pilot channel. However, these performance improvements have tradeoffs that adversely affect inactive devices.
For example, idle UEs infrequently “wake-up” to monitor network status. By increasing the pilot channel messaging, idle UEs have a greater decoding burden for negligible gain. Similarly, unconnected devices may be interested in monitoring the status of nearby networks (such as for later handover, ad hoc networking, etc.), but constant monitoring of unrelated pilot channel messaging may not be worth the extra operational burden. Existing solutions inefficiently dedicate radio resources for scanning neighboring information channels (e.g., there is a relatively low probability of successful detection, and neighboring pilot channel information provides very little useful information).
Thus, tradeoffs between the amount of information in an information channel, and the relative cost of extracting the information, continues to limit the feasibility of increased information channel complexity. Accordingly, improved methods and apparatus are needed to, inter alia, support improvements to pilot channel functionality, while still minimizing the impacts of such changes on inactive or uninterested receivers.